JPH0886380A - Pilot valve - Google Patents

Abstract

PURPOSE: To provide a pilot valve whereby the service life of pistons driving a valve element can be prolonged and made compact. CONSTITUTION: Piston boxes 11 and 12 are installed on both sides of a valve main body 4 of a main valve 1 which is provided with multiple ports and an axial valve hole 6, and protruded parts 13a and 15a extending to the valve hole are installed in cylinder chambers 13 and 15 which are provided in the piston boxes 11 and 12. Also pressing parts 14a and 16a which press a valve element 9 and recessed parts 14b and 16b on which the protruded parts slide are provided are provided on pistons 14 and 16 so as to guide the sliding of the pistons by the relative sliding movement of these protruded and recessed parts. Thus the service life of an active valve can be prolonged and made compact because it is not inclined even if the width of the pistons in sliding direction is small.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pilot type valve.

[0002]

2. Description of the Related Art A plurality of ports, a valve body slidably inserted in an axial valve hole in which these ports open, a first cylinder chamber and a second cylinder chamber provided at both ends of the valve hole, and A main valve having a first piston and a second piston that slide in these cylinder chambers; and a pilot valve,
A pilot type valve in which the valve element is slid by these pistons driven by the pilot fluid supplied to and discharged from the pilot valve into the first cylinder chamber to switch the communication between the ports is already known without any particular illustration. There is. However, the above-mentioned known pilot type valve has a problem that the piston that slides the valve element tends to tilt when driven, and therefore an unbalanced load acts on the piston to shorten its life.

In order to solve this problem, the width in the sliding direction may be made larger than the diameter of the piston, but if the width in the sliding direction is made larger than the diameter, the axial length of the cylinder chamber is increased. Is not preferable because the valve becomes large due to the long length.

[0004]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide a pilot type valve in which the piston has a long life and can be made compact.

[0005]

In order to solve the above-mentioned problems, a pilot type valve of the present invention comprises a plurality of ports, a valve element slidably inserted into an axial valve hole in which these ports open, A main valve having a first cylinder chamber and a second cylinder chamber provided at both ends of the valve hole, and a first piston and a second piston sliding in these cylinder chambers, and a pilot valve. In a pilot type valve in which a valve body is slid by these pistons driven by pilot fluid supplied to and discharged from the first cylinder chamber to switch communication between ports, a shaft facing a valve hole in one or both of the cylinder chambers. Direction projections, one or both of the pistons are provided with axial recesses into which the projections are inserted, and the movement of the piston is guided by relative sliding between the projections and the recesses. It is.

In order to solve the same problem, the first piston and the second piston are provided with a pressing portion which is loosely inserted into the valve hole and presses the valve body, and the tip of the recess is extended to the pressing portion. It is characterized by that.

Further, in order to solve the same problem, it is characterized in that the cross section of the convex portion or the concave portion in these pilot type valves is made non-circular.

[0008]

When the pilot fluid is supplied to and discharged from the pilot valve into the first cylinder chamber, it is pressed by the first and second pistons driving the first and second cylinder chambers, and the valve element reciprocates in the valve hole. Communication between ports switches. Since the piston slides by being guided by the relative sliding of the convex portion and the concave portion provided in the cylinder chamber and the piston, it does not tilt even if the width in the sliding direction is small. Therefore, the pilot type valve capable of preventing the partial wear of the piston due to the inclination can be made compact.

Further, since the piston is provided with a pressing portion for pressing the valve body and the tip of the concave portion is extended to the pressing portion, even if the concave portion is provided, the length in the cylinder chamber and piston axial direction will not be long. Absent.

[0010]

1 shows a first embodiment of the present invention, in which a pilot type valve comprises a main valve 1 and a pilot solenoid valve 2. The valve body 4 of the main valve 1 has a compressed air supply port P and discharge ports EA and EB on the lower surface in the drawing, output openings 5A and 5B on the opposite surface thereof, and these ports and output openings around the center. Adapters 7 each having an axial valve hole 6 that opens, and having output ports A and B that individually communicate with the output openings 5A and 5B on the opening surfaces of the output openings 5A and 5B. Is installed,
A valve body 9 for slidingly connecting the output ports A and B to the supply port P and the discharge ports EA and EB to communicate with each other is slidably inserted into the valve hole 6.

A first piston box 11 and a second piston box 12 are attached to both axial ends of the valve body 4 by appropriate means, and a first cylinder chamber 13 provided in the first piston box 11 is provided with a first cylinder box 13. 1 piston 14 is the second piston box 1
Second cylinder chamber 1 having a smaller diameter than the first cylinder chamber provided in 2.
The second pistons 16 are slidably inserted into the respective parts 5. Then, in the centers of the cylinder chambers 13 and 15, a first convex portion 13a and a second convex portion 15a having a circular cross section that extend toward the valve hole 6 are formed. The first piston 14 and the second piston 16 are provided with a first pressing portion 14a and a second pressing portion 16a which are loosely inserted into the valve hole 6 and press the valve body 9, and the convex portions 13a and 15a. A first recess 14b and a second recess 16b each having a circular cross section are formed, and the tips of these recesses extend to the pressing portion.

The pilot solenoid valve 2 has a pilot supply port, a pilot output port, and a pilot discharge port (all not shown). The solenoid 2a is excited and released to change the pilot output port to the pilot supply port and pilot discharge port. It is configured as a well-known 3-port solenoid valve that is switched to and communicates with and the pilot supply port includes a valve body 4 and a first piston box 1
1 through the pilot flow path 18 formed in the supply port P
The pilot output port and the pilot discharge port are both connected to the first
It communicates with the cylinder chamber 13 and the outside. Further, the second cylinder chamber 15 communicates with the supply port P by the passage 19 formed in the valve body 4 and the second piston box 12. However, the pilot valve of the present invention is not limited to an electromagnetically driven valve, and may be driven by an appropriate drive means such as mechanical drive.

Reference numeral 20 in FIG. 1 is a manual operation button for directly connecting the pilot passage 18 to the first cylinder chamber 13 by pressing, 21 is a communication hole for connecting a breathing chamber defined by the pistons 14 and 16, and 22. , 22 are seal packings fitted to the outer peripheral surfaces of these pistons.

In the first embodiment described above, when the pilot air in the first cylinder chamber 13 is discharged, the valve body 9 is driven by the air pressure in the second cylinder chamber 15, and the second piston 16 is driven.
It is pressed by the pressing portion 16a and slides to the left as shown in the lower half of the figure, and the supply port P and the output port B, and the output port A and the discharge port EA communicate with each other. When the solenoid 2a is excited and pilot air is supplied to the first cylinder chamber 13 from the pilot output port, the pressure receiving area difference between the pistons 14 and 16 causes the first piston 14 to slide and the pressing portion 14a to press the valve body 9. Therefore, the valve body 9 slides to the right as shown in the upper half of the figure, and the supply port P and the output port A and the output port B and the discharge port EB communicate with each other.

In this case, the pistons 14 and 16 have the recess 1
Since the protrusions 13a and 15a slide on the protrusions 4a and 16b, even if the width in the sliding direction is narrow, the protrusions and the recesses do not incline and smoothly slide to prevent an unbalanced load. Since it does not work, the valve can be made compact. Further, since the pistons 14 and 16 do not tilt, the seal packing 22 does not wear unevenly, so that the life of the piston can be extended. Further, since the tips of the recesses 14b and 16b are extended to the pressing portions 14a and 16a for pressing the valve body 9 provided on the pistons 14 and 16, even if the recesses are provided, the sliding direction of the pistons 14 and 16 is increased. There is no need to increase the width of. Therefore, the pilot-type valve capable of preventing uneven wear of the piston can be made more compact.

The convex portions 13a, 15 in the first embodiment described above
The cross-sectional shape of a is not limited to a circular shape, and may be any shape that can be inserted into the recesses 14b and 16b having a circular cross-section without radial play, and as shown in FIGS. It is possible to have a corner portion that is in sliding contact with the surface, and in this case, the contact area between the convex portion and the concave portion can be reduced. Further, the cross-sectional shape of the concave portions 14b and 16b is not limited to the circular shape, and may have a similar cross-sectional shape to the convex portions shown in FIGS. 2A and 2B, for example.

Pistons 14 and 16 sliding in the cylinder chamber
May not easily tilt depending on its axial width. In this case, it is possible to omit the convex portion of the cylinder chamber in which the piston, which is difficult to tilt, slides. FIG. 3 shows the second aspect of the present invention.
An example is shown. In this example, the second cylinder chamber 15 and the second piston 16 are provided with the second convex portion 15a and the second concave portion 16b, and the first cylinder chamber 26 formed in the first piston box 25 is shown.
Is not provided with a convex portion. Although the first piston 14 shown in the drawing is formed with the first recess 14b in order to make the parts common, the recess can be omitted if necessary. Since the other structure of the second embodiment is the same as that of the first embodiment, the same parts as those in the figure are designated by the same reference numerals and detailed description thereof will be omitted.

Although not shown, it is also possible to provide a convex portion and a concave portion on the first cylinder chamber and the first piston to omit the convex portion on the second cylinder chamber. Further, also in the second embodiment, the cross-sectional shapes of the convex portion and the concave portion can be set to the cross-sections shown in FIGS. 2A and 2B as in the first embodiment. Further, although the main valve 1 in each of these embodiments is a 5-port valve, the main valve of the present invention may be a 3-port valve or a 4-port valve.

[0019]

According to the pilot type valve of the present invention, one or both of the cylinder chamber and the piston are provided with an axial convex portion facing the valve hole and a concave portion on which the convex portion slides to form a valve body. Since the sliding of the pressing piston is guided, even if the sliding direction width of the piston is small, it does not tilt during sliding, so that the life of the piston can be extended and the valve can be made compact. Further, by extending the concave portion to the pressing portion that presses the valve body provided on the piston, the axial lengths of the cylinder chamber and the piston do not change even if the convex portion and the concave portion are provided, so the life of the piston is improved. The long pilot type valve can be made more compact.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a first embodiment.

2A and 2B are perspective views showing modified examples of a concave portion and a convex portion.

FIG. 3 is a vertical sectional front view of a second embodiment.

[Explanation of symbols]

 1 main valve 2 pilot solenoid valve 6 valve hole 9 valve body 13, 15, 26 cylinder chamber 13a, 15a convex part 14, 16 piston 14a, 16a pressing part 14b, 16b concave part P, A, B, EA, EB port

Claims (3)

[Claims] 1. A plurality of ports, a valve element slidably inserted in a valve hole in the axial direction in which these ports open, a first cylinder chamber and a second cylinder chamber provided at both ends of the valve hole, and The first piston and the second piston that slide in these cylinder chambers
A main valve having a piston, and a pilot valve, and the valve element is slid by these pistons driven by pilot fluid supplied to and discharged from the pilot valve to the first cylinder chamber,
In a pilot type valve that switches communication between ports, one or both of the cylinder chambers are provided with an axial convex portion facing the valve hole, and one or both of the pistons are provided with an axial concave portion into which the convex portion is inserted. And a guide valve for guiding the movement of the piston by the relative sliding of the convex portion and the concave portion. 2. The first piston and the second piston are provided with a pressing portion that is loosely inserted into the valve hole and presses the valve element, and the tip of the recess is extended to the pressing portion. Item 1
Pilot type valve described in. 3. The pilot type valve according to claim 1, wherein the convex portion or the concave portion has a non-circular cross section.